Coolant return system



Nov. 13, 1956 B. P. GRAVES COOLANT RETURN SYSTEM 2 Sheets-Sheet 1 Filed April so, 1953 United States Patent COOLANT RETURN SYSTEM Benjamin P. Graves, Providence, R. L, assignor to Brown & Sharpe Mfg. Company, Providence, R. 1., a corpora- The present invention relates to an improved coolant system for use in a milling machine.

It is the usual practice in milling and similar metal cutting operations to direct a stream of coolant against the work and tool at the point of cutting contact. The very substantial volume of liquid thus poured onto the machine falls in large part onto the work supporting table and onto adjacent portions of the relatively movable members of the work supporting assembly, and is drained by means of suitably formed surfaces and conduits to a reservoir in the base of the machine.

In a milling machine of the general type having a vertically adjustable knee and a plurality of supports mounted one upon the other from the knee and movable in a plurality of directions, a major portion of the return coolant is collected upon the work supporting table and is drained through passages formed in the table and in one or more of the associated supports to an open reservoir or pan, which forms a base for the machine.

It will be understood that in addition to the coolant, which is returned or drained from the work support assembly of the machine in the manner described, large quantities of metal chips are carried away from the point of cutting contact with the work and are washed downwardly with the return coolant into the pan at the base of the machine. As the rate and depth of metal cutting has increased with corresponding increases in the volume of coolant required, a serious problem has been encountered in a substantially increased tendency of the metal chips to accumulate and to block the passages by which the coolant is returned to the pump with consequent loss of eificiency of machine operation.

It is a principal object of the present invention to provide a novel construction and arrangement of the coolant return surfaces and passages to avoid clogging of these passages, and to provide easy access of the operator for ready removal of such chip accumulations as may occur.

It is a further object of the invention to provide a conduit of novel and improved construction through which a substantial portion of the coolant and chips are returned from a collecting reservoir in the clamp bed or saddle of the machine to the reservoir in the base, which is constructed and arranged to avoid excessive accumulations of chips, is readily accessible, and is readily removable for cleaning and repair.

With these and other objects in view, as may hereinafter appear, the several features of the invention consist in the devices, combinations, and arrangement of parts hereinafter described and claimed, which, together with the advantages to be obtained thereby, will be readily understood by one skilled in the art from the following description taken in connection with the accompanying drawings, in which Fig. l is a view in embodying in a preferred form the several features of the coolant return system of the present invention;

Fig. 2 is a view in left side elevation of the base and perspective of a milling machine work supporting assembly of the machine, with portions of the work table and swivel support sectioned to illustrate particularly the path taken by the coolant during its return from the work table to the reservoir in the base;

Fig. 3 is an enlarged sectional detail view of the telescoping conduit, by means of which the coolant and any chips washed along therewith are returned to the reser- V011;

Fig. 4 is an enlarged detail sectional view taken on line 4-4 of Fig. 2 to illustrate particularly the roller support and track on which the coolantconduit referred to is supported; and

Fig. 5 is a detail view in perspective looking from the left side of the machine showing particularly the arrangement of the coolant drainage connections between the swivel saddle support and table, by means of which the coolant is returned to the reservoir in the base.

The invention is illustrated in a preferred form as embodied in a milling machine having a column on which is mounted a forwardly projecting tool spindle and a work supporting assembly comprising a knee vertically slidable on ways on the column, and a plurality of support members mounted one upon another from the knee for movement in a plurality of horizontal directions.

In the illustrated machine, coolant supplied at the point of cutting contact ispoured onto the work supporting table and is collected in a drainage slot in the swivel carriage support shown, from which the coolant flows into a drainage basin formed on the clamp bed on which the carriage support is swiveled and, which, is in turn mounted for forward and back movements on ways on the vertically movable knee. Finally, the coolant together with the chips collected in the basin on the clamp bed pass downwardly through a telescoping conduit into an open coolant collecting pan formed above the coolant reservoir in the base of the machine.

In accordance with the invention, the coolant return system is specifically constructed and arranged to collect and to return to the pan on the top of the base reservoir a maximum return flow of coolant, and to carry away therewith any quantity of chips which may be formed. It is contemplated that the chips will be deposited on the pan while the coolant is allowed to return through the usual covers to the reservoir beneath. The system is particularly constructed and arranged to provide access to the operator to all parts of the system for the clearing away of any excessive accumulation of chips which may be formed.

A feature of the invention consists in the provision of a novel coolant drainage connection comprising a telescoping pipe through which the coolant and chips are returned from the work supporting assembly to the pan and reservoir in the base. In the preferred form of the invention shown, the telescoping pipe, referred to, is connected with a drainage basin formed on the clamp bed of the machine, and is accessible for cleaning or removal from the machine, if so desired. The location of the telescoping pipe, for movement along one edge of the coolant collecting pan, is of particular advantage to avoid troublesome accumulations of chips which would interfere with the free flow of coolant to the reservoir, and to provide easy access to all parts of the reservoir for cleaning.

Referring more specifically to the drawings in Fig. 1, a milling machine is shown having a column 10, provided with a laterally offset housing 12, in which is carried a machine tool with spindle 14 and two overarm bars 16. The work supporting assembly of the machine comprises a knee member 18 which is arranged for vertical sliding movements on ways 20 mounted on the left side of column 10, and which is supported for such movement by means of a supporting and lifting screw 22. A clamp Patented Nov. 13, 1956 bed 24 is mounted for a forward and back movement on the ways formed on the knee member 18. A swivel carriage support 26 swivelled on the clamp bed 24 is provided with ways 28 to receive transversely movable work table 30. Inasmuch as the specific arrangement of the several supports of the tool support assembly and the actuating mechanism therefor -forms specifically no part of the present invention, and is more particularly described in a separate application for Letters Patent about to be filed in the United States Patent Oflice, any detailed description of these parts is believed unnecessary, and is therefore omitted.

Coolant is supplied to the point of cut-ting contact of the machine from a reservoir 33 which is formed with a coolant collecting pan 34 thereon in the base of the machine by means of coolant pump 36, flexible hose connections and a nozzle 37 which may be of any description, and which are therefore not here further referred to.

The drainage connections, through which the coolant supplied at the point of cutting contact is returned to the base, comprise a plurality of cross passages in the table, such as that indicated at 40 in the sectioned portion of Fig. 2, and a drainage slot 42 which extends along the rear side of the table. A drain pipe 44 projects downwardly from a low point of the slot 42. Coolant flowing from the drain pipe 44 is collected in a drainage slot 46 which extends along the rear side of the carriage swivel support 26, and is in turn provided at its low point with a drainage pipe 48 which empties onto a drainage surface 50 formed on the top surface of the clamp support 24. The surface 50 slopes downwardly in a forward direction, as best shown in Figs. 2 and 5, into a drainage basin 52 having a funnel shaped outlet 54. Coolant and chips, which find their way onto portions of the clamp support rearwardly of the table, will be drained downwardly into the basin 52 over the sloping surface 50. In order to provide for proper drainage from the pipe 48, when the table 30 and swivel saddle support 26 are rotated in a clockwise direction to the position shown in Fig. 5, an additional drainage surface 56 is provided which is located along the curved path taken by the pipe 48 and also slopes downwardly into the drainage basin 52.

Specifically, in accordance with the invention, the coolant and any chips which may be washed along therewith are carried downwardly from the drainage basin 52 into the open coolant collecting pan 34 through a telescoping conduit 58 which is secured at its upper end into the funnel shaped outlet 54, and at its lower end opens into the coolant collecting pan 34. As best shown in Fig. 3 the telescoping conduit 58 is formed with a tubular base portion 59, having formed at opposite sides thereof at its lower end two laterally extending ears 60 recessed at 62 to receive rollers 64 which are supported to turn on pivots 66 on the ears 60. The rollers 64 provide a rolling support for the telescoping pipe 58 on the rail 68 formed on one side of the pan 34. The tubular base member 59 is further slotted along its bottom edge at 70 to receive the rail 68. Within the tubular stern of the member 58 are mounted three telescoping sections of pipe, 72, 74 and 76. The section 76, at its upper end, is fitted over the funnel outlet 54 and is connected thereto by a removable pin 78. As best shown in Fig. 4 the base member 59, of the telescoping conduit 58, is formed with an offset outlet 80 through which the coolant and chips are discharged toward the middle of the pan 34'. The coolant drains from the pan 34 into the reservoir 33 beneath through openings provided by loosely fitting clean out covers indicated at 81 in Figs. 1 and 2.

The manner in which the drainage connections operate, to collect and to channel into the reservoir 34 any quantity of coolant poured onto a work piece supported on the table 30 for any position which may be assumed by the several supports of .the work supporting assembly,

will be readily appreciated from an inspection of the drawings. 7

A major portion of the coolant will be collected in the table passages and will flow downwardly through the drain pipe 44 into the drainage slot 46 which is of sufiicient length to connect with the drain pipe 44 for any position of the table on the swivel saddle support 26. Coolant flowing from the drain pipe 48 is collected on the surface 50 or 56, depending upon the angular position of the swivel saddle support 26, and flows into drainage basin 52 and drain pipe 58, and thence into the coolant collecting pan 34. Any coolant which may find itsway over the edge of the table onto the surface 50 of the clamp bed will be sirnilarlyre'turned through the drainage basin S2 and telescoping drain pipe 58 into the pan 34.

With the improved construction illustrated the telescoping drain pipe 58 is independently supported and guided at its lower end for movement in a forward and back direction in the machine with the clamp bed 24. The drain pipe is freely extended and collapsed with the upward and downward movement with the entire'work supporting assembly including the knee on ways '20. The outlet from the telescoping'pipe is located at all times adjacent the surface of the mg.

With the arrangement shown, the chips formed will be washed downwardly with the coolant through the telescoping drain pipe 58' and will be deposited toward the center of the pan 34 and out of the path of forward and back movement of the drain pipe 58 along the edge of the pan. The arrangement is such as to provide easy access for the operator to clean the drain pipe of any residue of chips which may be accumulated within the pipe, and the pipe is further readily removable from the machine, if desired. To this end his required only to remove pin 78 which is employed to fasten the topmost portion 76 of the telescoping pipe to the funned shaped outlet 54 of the drainage basin 52. v

The invention having been described, what is claimed is:

1. In a milling machine having a base, a machine column, and a work supporting assembly including a knee vertically adjustable on the column, and a plurality of supports mounted one on the other for movement in a plurality of directions for transverse m'ovementon the knee, the combination of a coolant reservoir having a coolant collecting thereon in the base, a drainage basin for coolant fon the clamp bed, and a telescoping pipe providing an unobstructed passageway betweenthe drainage basin andthe pan, means securing the telescoping pipe for movement as a unit with the clamp bed, and means supported fi orn the base for maintaining the lower end of said ipe spaced above the pan. a p

2. In a milling machine having a base, a machine column and a work supporting assembly including 'ak n'ee vertically adjustable on the column, and a support horizontally movable on the knee, the combination or a coolant reservoir having a coolant collecting pan in'the base, a drainage basin 'fo'r coolant on the movable support having open'drainag'e surface sloping thereto, and a telescoping pipe including upper and lower telescoping pipe sections depending from and providing an uneastructed straight line downward passageway for coolant and chips from the drainageb'asin to the pan, means securing the upper telescoping pipe section to move as a unit withsaid horizontally movable support, and means supporting the lower telescoping pipe section with the lower end thereof spaced above the pan;

3. in a milling machine having a base, a machine column, and a work supporting assembly including a knee vertically adjustable on the column and asupport movable on the knee in a horizontal direction, the cornbination of acoolant reservoir having a coolant collect ing pan thereon inthe base, a drainage basin for coolant pan 34 to avoid splash including a clamp bed mounted on said movable support, a telescoping pipe including upper and lower telescoping pipe sections depending from the drainage basin providing an unobstructed vertical passageway for coolant and chips and having its outlet over the pan, releasable fastening means connecting the upper telescoping pipe section to the drainage basin, a guideway on the base, and rollers on which the lower telescoping pipe section is supported for movement with the support and with the lower end thereof spaced above the pan.

4. In a milling machine having a base, a machine column, and a work supporting assembly including a knee vertically adjustable on the column, and a plurality of supports movable upon one another in a plurality of directions including a clamp bed supported on the knee for forward and back movement, the combination of a coolant reservoir having a coolant collecting pan thereon in the base, a drainage basin for coolant on the clamp bed accessible from above for cleaning and open drainage surfaces on the clamp bed sloping downwardly to the basin, drainage connections from said plurality of supports onto said drainage surfaces, and a telescoping pipe rigidly secured to and movable as a unit with the clamp bed depending from the drainage basin providing an unobstructed vertical passageway for coolant and chips to the pan including upper telescoping pipe section rigidly secured to and movable as a unit with the clamp bed, a lower telescoping pipe section and a guideway along the edge of the pan on which the lower telescoping pipe section is supported with the lower end thereof spaced above the pan 5. In a milling machine having a base, a machine column and a work supporting assembly including a knee vertically adjustable on the column, a clamp bed movable in a forward and back direction on the knee, a saddle support swivelled on the clamp bed, and a work table slidably mounted on the saddle support, the combination of a coolant reservoir having thereon a coolant receiving pan in the base, an open drainage basin for coolant and coolant drainage surfaces sloping thereto on the clamp bed, drainage connections from the table and saddle support onto said surfaces, a telescoping drainage pipe having upper and lower telescoping sections providing a vertical conduit for coolant and chips from the drainage basin to the pan, detachable fastening means for securing the upper telescoping pipe section to the drainage basin, a guideway on the edge of the pan, and means connected with the lower telescoping pipe section and engaging said guideway to support said lower telescoping pipe section spaced above the pan.

References Cited in the file of this patent UNITED STATES PATENTS 647,413 Johnson Apr. 10, 1900 995,256 Kearney et a1. June 13, 1911 1,518,154 La Ducer Dec. 9, 1924 1,938,777 Nenninger Dec. 12, 1933 2,507,437 Eserkaln May 9, 1950 

